Page 30 - Curriculum Visions Dynamic Book

Steelmaking
Steel is mostly made of iron, but many
of the impurities have been taken out, and controlled amounts of other compounds have been added.
Iron contains about 5% carbon and small amounts of manganese, silicon, phosphorus and sulphur. The steelmaking process aims to reduce the carbon level to below 1.75% by oxidising iron with oxygen from the air.
 The basic oxygen furnace process of steelmaking.
A jet of oxygen is blown
over the molten metal.
Molten pig iron, scrap steel and lime are loaded into the furnace.
Refining the steel
Steel furnaces are the first step in steelmaking. The charge material is collected in a giant steel furnace, where a jet of inert gas such as argon is blown through
it so that the steel is stirred and made more uniform. It may then be treated to reduce sulphur and other impurity levels even further. Only then does it go to the mills to be rolled into sheets or made into shapes such as girders, bars and wire.
Also...
The electric arc process
is another way to produce molten steel, but it is essentially a melting process for scrap steel, and chemical reactions do not play a major part in it.
The furnace can rotate
EQUATION: Iron is oxidised, releasing heat
Iron + oxygen ➪ iron oxide 2Fe(s)+ O2(g) ➪ 2FeO(s)
heat is released
EQUATION: Silicon impurities are oxidised using lime
Iron oxide + silicon + lime ➪ steel + slag 2FeO(s) + Si(s) + CaO(s) ➪ 2Fe(s) +CaSiO3(s)
EQUATION: Excess carbon in the iron is removed
Iron oxide + carbon in the iron ➪ steel + carbon monoxide gas
FeO(s) + C(s) ➪ Fe(s)
When the reaction is complete the furnace is tilted to pour steel into ladles.
Steel-rolling mills
+ CO(g)
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